Role of Intramuscular PAI-1 During Aged Skeletal Muscle Regeneration
Bibliographic record
Abstract
Role of Intramuscular PAI-1 During Aged Skeletal Muscle Regeneration S.A. Angus, F.A. Rahman & M.P. Krause Department of Kinesiology, University of Windsor, ON N9B 3P4, Canada. Primary author: anguss@uwindsor.ca Introduction: Skeletal muscle regeneration is a crucial process in returning muscle to its original function following damage. The accumulation of the extracellular matrix (ECM) is an important, yet often overlooked aspect during the regeneration process. With age, there is a decline in the regenerative capacity of skeletal muscle, partly attributed to the accumulation of the ECM, called fibrosis. Therefore, investigation into the contributors of fibrosis, namely plasminogen activator inhibitor-1 (PAI-1), is needed to better understand changes in the ECM during regeneration in aged muscle. Methods: Young (3 month old) and aged (18 month old) male C57BL/6J mice were studied (n = 15). Muscle damage was induced via cardiotoxin (CTX) injection to the left tibialis anterior muscle. Mice were sacrificed at 3, 5 and 7 days following damage and muscles were collected. Immunohistochemical (IHC) techniques were used to investigate regenerative capacity, macrophage density, and macrophage-derived PAI-1 expression. A two-way ANOVA was used to determine statistical significance for the results. Results: Myogenic potential of aged skeletal muscle was found to be significantly lower in the 7-day post-damage compared to young (main effect: p < 0.05). In addition, a significant increase in macrophage count at 7-day post-damage in aged skeletal muscle was observed. There was a significant difference in macrophage-derived PAI-1 content throughout the regeneration process between groups (p < 0.05). Discussion: Aged skeletal muscle was observed to have a diminished regenerative capacity as well as an increase in prolonged necrosis following damage. These findings suggest that the implications of macrophage-derived PAI-1 may have a negative effect on the ECM and the regenerative capacity of aged skeletal muscle.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".